Field Journal • Offline-First Agronomy & Field Notebook

Field Journal

An expedition-grade Android field notebook for land stewardship, agronomy trials, wildlife monitoring, and acoustic surveying.

↓ GitHub Repository ⧉ Installation Guide

Field-Engineered Display Modes

Tested under extreme field lighting: bright open canopy, evening dusk shade, and tactical zero-lux red to preserve natural dark-adapted vision.

Optical Lens Viewfinder HUD
Optical Lens HUD
Offline Property Map & USGS Topo
USGS Topo & Scrubber
Field Journal Logbook Cards
Journal Entries
Acoustic Mel Waterfall Spectrogram
Mel Spectrogram
Specifications & Calibration Plate
Calibration Plate

Strict Privacy & Offline Autonomy

Zero tracking. Zero cloud lock-in. No accounts. Field Journal operates completely air-gapped with all SQLite records, geotags, photos, and WAV audio clips stored strictly on your local device filesystem. Export anytime as clean Obsidian-ready Markdown frontmatter bundles and JSON zips. Optional sensor station feeds and AI enrichment use direct peer-to-peer or self-hosted endpoints with no middleman.

Core Capabilities

⊙ Optical Lens & Rangefinder

CameraX viewfinder HUD with pitch, azimuth, and trigonometric distance estimation based on calibrated eye height. Dual-ray (Ray A / Ray B) vector intersection accurately triangulates distant landmarks and wildlife sightings without moving to target.

⧉ Zero-Key USGS & OSM Maps

Keyless USGS Topo, Aerial Imagery, and OpenStreetMap Mapnik tiles with custom color-matrix night/dusk shaders. Single-link clustering groups field observations, while a 12-month season ruler displays cumulative base-50°F Growing Degree Days (GDD).

∼ Mel-Waterfall Spectrogram

Built-in 16 kHz mono acoustic recorder with Hann-windowed FFT and 64-bin mel waterfall normalisation. Visualise bird calls, amphibian choruses, and equipment harmonics directly in the field guide feed.

↑ Zero-Typing Environmental Stamp

Every note automatically binds hardware barometric pressure (hPa), 3-hour microbarograph pressure trend, relative elevation offset, GPS accuracy, and compass bearing with zero keyboard entry required.

§ Obsidian Vault Export

Exports notes directly into standard YAML frontmatter Markdown files with tags, wikilinks ([[Vault: Note]]), GPS coords, and embedded media, ready to open in Obsidian or sync via git.

Δ Glove & Physical Controls

Designed for damp field gloves: volume keys double as hardware triggers (hold Volume Down for speech recognition, tap Volume Up to snap) with high-contrast WCAG AA tactile plates.

Installation

Build directly from source or download debug APK artifacts from GitHub Actions CI:

  1. Clone repository: git clone https://github.com/charles-forsyth/field-journal.git
  2. Set JDK 17 and Android SDK: 
    export JAVA_HOME=$(brew --prefix openjdk@17)/libexec/openjdk.jdk/Contents/Home
./gradlew assembleDebug
  3. Install on device: 
    adb install app/build/outputs/apk/debug/app-debug.apk

Citation

If you use Field Journal in research, agronomy field trials, or wildlife monitoring, please cite:

@software{forsyth2026fieldjournal,
  author       = {Forsyth, Charles E. III},
  title        = {Field Journal: an offline-first Android field notebook for land, wildlife and agronomy},
  version      = {1.2.0},
  year         = {2026},
  doi          = {10.5281/zenodo.23755518},
  url          = {https://github.com/charles-forsyth/field-journal}
}

DOI: 10.5281/zenodo.23755518 • License: MIT